I don't think the newspaper article linked to is very good, most of the ornamentals mentioned aren't collector antiques and some are modern staples. Other quibbles: What would be the point of avoiding named varieties of flowering quince? The implication is the Chaenomeles speciosa (which is not identified as such, I believe, as though the writer doesn't know that's what it's called) is a better do-er, but I don't think that is necessarily the case. And what is Philadelphus coronarius "Flore Pleno"? (Cultivars are shown in double quotes, another indication that in-depth familiarity with the topic is lacking - unless these were inserted by somebody else after the piece was submitted). A mistake for P. mexicanus 'Flore Pleno'?
Yeah, it is sort of fluff piece. I chose it maily because it came from a NW source. Sorry, I will try to make sure to choose more carefully written articles in the future. I don't think the point of growing heirloom plants is necessarily to grow collector antiques. It is just good to know that some of the plants we grow have a history, whether they are rare or not.
Another source of leads on proven plants are awards, such as the RHS Award of Garden Merit, Pennsylvania Hort. Soc. Gold Medal, Great Plant Picks and so forth. However, plants so designated may still prove problematic for a particular gardener, especially here in North America where there are so many different climates, soils, and gardeners. And some plants that keep being awarded just don't fit the basic criteria in the first place, for example disease-susceptible Paul's scarlet hawthorn keeps getting the AGM.
